Monday, September 18, 2017

Are Caribbean Islands Uninhabitable Due to Global Warming Fueled Hurricanes?

There is no way to know whether the series of hurricanes that have barreled across the Atlantic toward the islands of the Caribbean: a) foreshadow a trend, or b) have been due to favorable conditions unique to this hurricane season. But it is indisputable that these storms have intensified unusually quickly and are dropping huge amounts of rain. Global warming has made Harvey, Irma, and Maria particularly ferocious. Irma was the strongest Atlantic hurricane ever, and Hurricane Maria is the second fastest to reach Category 5. And in addition to Harvey, Irma, Jose and Maria in 2017, last year, Hurricane Matthew underwent a remarkable rapid intensification of 80 mph in 24 hours, intensifying from a Category 1 hurricane to a Category 5 hurricane.

The 2017 season has reversed the "so-called" hurricane drought of the past decade. This year could turn out to be an outlier, and the next few years could return to the relative tranquility of the past decade. But the ongoing warming of the waters of the Atlantic may have led to a tipping point being reached. Major hurricanes may hit the Caribbean islands with increasing frequency in the future. And if this year becomes the new normal, then many of the Caribbean islands are uninhabitable. Barbuda has already been evacuated, and unfortunately it may not be the last island that has to be evacuated. Time will tell whether Barbuda will be rebuilt.

More Information
Number of cat 5 hurricane landfalls on an island in the Lesser Antilles:
1851-2016 : Hurricane David in 1979 
2017: 2 #Irma, #Maria

3 reasons why America’s ‘major hurricane drought’ is misleading - PBS
Hellish Intensification — Maria’s Winds Jump 50 mph to CAT 5 Strength in Just 12 Hours -
Storms are Getting Stronger - NASA
Rapid Intensification - Hurricane Wiki

Friday, August 25, 2017

Probability Only 0.7 Percent of Record Global Temperatures In 3 Consecutive Years

The slow pace of climate change is masked by the huge variability of weather. Thus, climate change is not readily perceptible as it has so little impact from year to year compared to the variability of weather. As an extreme example, Chicago experienced an 83-degree temperature span between the 1982 December 21st 62-degree high and the low of minus 21 on the same date in 1983. This variability of weather on an annual basis is certainly one of the factors behind the failure of many Americans to recognize that global warming is changing the global climate.

Another factor that contributes to the apathy regarding the consequences is that so many of the articles about climate change focus on the cataclysmic effects that can be expected in 2100 (83 years in the future).  While these cataclysmic predictions support attention grabbing headlines, for those that are skeptical about climate science/global warming, the conjectures about impacts that may occur long after their deaths is likely little more than white noise.

However, a recently published study contained a metric that is challenging to ignore. During 2014, 2015, and 2016, each year set a new record for hottest year in recorded history. The likelihood of three consecutive record-breaking years happening any time since 2000 is no more than 0.7 percent. This remarkable string of record breaking hot years refutes the claims that "the climate is always changing". The fingerprints of human-caused climate change are all over the string of record hot years.

A greater focus on the 0.7 percent chance of 3 consecutive record breaking hot years is one of the most compelling metrics available to combat the apathy and skepticism of climate science doubters. Amplifying the communication of this metric is a quick and easy way to get across an important and straight forward to understand aspect of the climate change message. 

Saturday, March 4, 2017

Has Global Sea Level Rise Increased to 5 mm Per Year?

There has not been a great deal of media coverage about the past 3 years of increase in the rate of sea level rise. Global sea levels have risen by an average of about 5 mm (0.2 inches) in each of the past 3 years. This is a significant increase versus in 3.3 mm (0.13 inches) increase per year during the satellite era (1993 to present). As shown below, the rate of sea level rise jumped up above the trend line in late 2014 and continued to rise in 2015. Sea level rise has remained above the trend, with another big jump in the most recently posted result (the period ending November 30, 2016)

Is sea level rise accelerating? There are a couple of valid reasons to question whether the past 3 years signals an increase in the rate of sea level rise. Time will tell whether an increase in the rate of sea level rise began in 2015 or not.
  1. The increase in sea level rise during the last three years may be due to El Nino. The warm global temperature and other weather impacts of El Nino may have produced the increase in the annual sea level rise. Sea level rise may revert back to 3.3 mm per year in non-El Nino years. 
  2. Three years of higher sea levels is probably not a long enough period to confirm a change in the trend of sea level rise. Although the increase in sea level rise during the satellite era is on a fairly linear trend, the annual results are rather noisey. However, if the past three years does indicate that sea level rise is now increasing at a faster pace, the consequences for coastal areas are dramatic. 
Whether or not an acceleration in the rate of sea level rise has begun has enormous implication for the future of coastal areas. Thirty years of 0.13 inches of sea level rise would result in a 4 inch increase. However, thirty years of 0.2 increases would lead to a 6 inch increase. Tidal flooding is already a serious problem. An additional 2 inches of sea level rise (6 instead of 4) would lead to billions of dollars in damage.

And of course, many climate researches are predicting that the rate of sea level rise is going to go parabolic, and that 6 inches of sea level rise in the next 30 years is an unrealistically optimistic scenario. As shown below, the NOAA intermediate prediction (green line) is for about 1 1/2 feet of sea level rise within the next 30 years.